1. Field
The present invention relates to a method and system for optical transmission delay compensation, and more particularly, a method and system for optical transmission delay compensation for compensating for a data delay time for synchronizing repeaters connected to each other through an optical transmission line in a mobile communication system.
2. Description of the Related Art
FIG. 1 is a configuration diagram of a mobile communication system having a main unit (MU)-remote unit (RU) structure. As shown in FIG. 1, when a main unit 10 and a plurality of remote units 20 respectively located at different distances from the main unit 10 are matched with each other through an optical transmission line, large-capacity signal transmission may be performed. Such a mobile communication system has an advantage that data signals may be transmitted over a long distance due to a low loss characteristic of the optical transmission line.
When the main unit 10 and the plurality of remote units 20 are separated from each other by a relatively large distance corresponding to several kilometers to several tens of kilometers, each forward baseband signal transmitted from the main unit 10 and reaching each of the plurality of remote units 20 has time delay proportional to each distance. Since the time delay of the different forward baseband signals makes RF propagation times of the respective remote units 20 different, it may result in a fatal error in hand off when a mobile station MS of a mobile communication terminal subscriber moves from the current location (e.g., a location where RU #1 is responsible) to another location (e.g., a location where RU #3 is responsible). This is because handover may be performed only when phases of transmission signals in all of RU #1, RU #2, and RU #3 of each of the plurality of remote units 20 are the same.